Wheel speed sensing system and method

Abstract

An improved speed sensing system is disclosed for a machine, such as a truck, that has an axle with an end and an axis. The machine further includes a sensor non-rotatably coupled to the end of the axle and coaxial with the axis. A wheel hub is rotatably coupled to the axle and a wheel cover is coupled to the wheel hub. The machine further includes a magnet coaxially disposed with the axis and coupled to the wheel cover for rotation about the axis as the wheel rotates. The sensor generates signals based on the rotational speed of the magnet and the wheel. For non-rotating axles that are solid or include solid spindles, a passageway for a communication line between the sensor and electronic control module (ECM) may be easily drilled thereby making the disclosed system easy to add to an existing machine or vehicle.

1. A machine comprising:
 a non-rotating axle having an end and an axis; 
 a sensor coupled to the end of the axle coaxially with the axis; 
 a wheel hub rotatably coupled to the axle; 
 a wheel cover coupled to the wheel hub; and 
 a magnet axially disposed on the axis and coupled to wheel cover, wherein the magnet is adjacent to the sensor and the sensor and the magnet do not overlap so that no line perpendicular to the axis intersects both the sensor and the magnet. 
 
     
     
       2. The machine of  claim 1 , wherein the magnetic flux lines of magnet extend generally perpendicular to the axis. 
     
     
       3. The machine of  claim 1 , wherein the sensor is non-rotatably coupled to the axle and the magnet is coupled to the wheel cover for rotation with the wheel cover and the wheel hub. 
     
     
       4. The machine of  claim 1 , wherein the end of the axle is coupled to a retainer, the retainer is disposed between the end of the axle and the wheel cover, the retainer includes a through-opening coaxial with the axis, the magnet is rotatably supported within the through-opening. 
     
     
       5. The machine of  claim 1 , wherein the wheel cover is coupled to a member, the member extends inwardly towards the axle along the axis, and the magnet is coupled to the member. 
     
     
       6. The machine of  claim 1 , wherein the axle is coupled to a retainer. 
     
     
       7. The machine of  claim 6 , wherein the retainer includes a through-opening that is coaxial with the axis and the magnet is rotatably supported within the through-opening of the retainer. 
     
     
       8. The machine of  claim 7 , wherein the wheel cover is coupled to a member, the member extends inwardly towards the retainer along the axis, the magnet is coupled to the member and rotatably supported in the through-opening of the retainer. 
     
     
       9. The machine of  claim 1 , wherein the end of the axle is supports a retainer disposed along the axis, and the sensor is disposed between the axle and retainer. 
     
     
       10. The machine of  claim 1 , wherein the axle includes an internal passageway extends inward from the sensor for accommodating an electrical connection between the sensor and an electronic control module (ECM). 
     
     
       11. A vehicle comprising:
 an electronic control module (ECM); 
 a non-rotating axle having an end and a longitudinal axis; 
 a sensor coaxially coupled to the end of the axle and coaxial with the axis; 
 a wheel hub rotatably coupled to the axle so the wheel hub rotates about the axis; 
 a wheel cover coupled to the wheel hub; 
 a magnet coupled to the wheel cover and axially disposed on the axis, wherein the magnet is adjacent to the sensor and the sensor and the magnet do not overlap so that no line perpendicular to the axis intersects both the sensor and the magnet; and 
 the axle includes a passageway that extends inward from the sensor that accommodates an electrical connection between the sensor and the ECM. 
 
     
     
       12. The vehicle of  claim 11 , wherein the magnetic flux lines of magnet extend generally perpendicular to the axis. 
     
     
       13. The vehicle of  claim 11 , wherein the vehicle is a truck that includes an anti-lock braking system (ABS). 
     
     
       14. The vehicle of  claim 11 , wherein the wheel cover is coupled to member, the member extends inwardly towards the axle along the axis, and the magnet is coupled to the member. 
     
     
       15. The vehicle of  claim 11 , wherein the axle is coupled to a retainer. 
     
     
       16. The vehicle of  claim 15 , wherein the wheel cover is coupled to a member, the member extends inwardly towards the retainer along the axis, the retainer includes a through-opening disposed along the axis, the magnet is coupled to the member and is rotatably supported in the through-opening. 
     
     
       17. The vehicle of  claim 11 , wherein the end of the axle is coupled to a plug and a retainer disposed along the axis, the sensor is disposed between the plug and the retainer. 
     
     
       18. A method of sensing rotational speed of a wheel mounted on a non-rotating axle of a vehicle, the vehicle includes an electronic control module (ECM), the non-rotating axle having an end and an axis, the axle is rotatably coupled a wheel hub so the wheel hub rotates about the axis, the wheel hub is coupled to a wheel cover, the method comprising:
 providing an internal passageway in the axle; 
 coupling a sensor coaxially with the axis to the end of the axle; 
 coupling a magnet to the wheel cover so that the magnet is axially disposed on the axis, wherein the magnet is adjacent to the sensor and the sensor and the magnet do not overlap so that no line perpendicular to the axis intersects both the sensor and the magnet; 
 coupling the sensor to an electronic control module (ECM) with a line that extends through the passageway of the axle; 
 rotating the wheel so that the magnet rotates about the axis; 
 generating a signal at the sensor relative to the rotational speed of the magnet; 
 communicating the signal to the ECM. 
 
     
     
       19. The method of  claim 18 , further includes coupling the wheel cover to member that extends inwardly towards the axle along the axis and supporting magnet along the axis with the member. 
     
     
       20. The method of  claim 18 , wherein the vehicle is a truck that includes an anti-lock braking system (ABS).